NAME

       Mail::Box::Locker::NFS - lock a folder with a separate file, NFS-safe

INHERITANCE

        Mail::Box::Locker::NFS
          is a Mail::Box::Locker
          is a Mail::Reporter

SYNOPSIS

        See Mail::Box::Locker

DESCRIPTION

       Like the "::DotLock" locker, but then in an NFS-safe fashion.  Over NFS, the creation of a
       file is not atomic.  The "::DotLock" locker depends on an atomic "open" system call, hence
       in not usable to lock a folder which accessed over NFS.  The "::NFS" locker is therefore
       more complicated (so therefore slower), but will work for NFS --and for local disks as
       well.

       Extends "DESCRIPTION" in Mail::Box::Locker.

METHODS

       Extends "METHODS" in Mail::Box::Locker.

   Constructors
       Extends "Constructors" in Mail::Box::Locker.

       Mail::Box::Locker::NFS->new(%options)
            -Option --Defined in       --Default
             expires  Mail::Box::Locker  1 hour
             file     Mail::Box::Locker  undef
             folder   Mail::Box::Locker  <undef>
             log      Mail::Reporter     'WARNINGS'
             method   Mail::Box::Locker  'NFS'
             timeout  Mail::Box::Locker  10
             trace    Mail::Reporter     'WARNINGS'

           expires => SECONDS
           file => FILENAME
           folder => FOLDER
           log => LEVEL
           method => STRING|CLASS|ARRAY
           timeout => SECONDS|'NOTIMEOUT'
           trace => LEVEL

   Attributes
       Extends "Attributes" in Mail::Box::Locker.

       $obj->expires( [SECONDS] )
           Inherited, see "Attributes" in Mail::Box::Locker

       $obj->timeout( [SECONDS] )
           Inherited, see "Attributes" in Mail::Box::Locker

   The Locker
       Extends "The Locker" in Mail::Box::Locker.

       $obj->filename( [$filename] )
           Inherited, see "The Locker" in Mail::Box::Locker

       $obj->folder( [$folder] )
           Inherited, see "The Locker" in Mail::Box::Locker

       $obj->name()
           Inherited, see "The Locker" in Mail::Box::Locker

   Locking
       Extends "Locking" in Mail::Box::Locker.

       $obj->hasLock()
           Inherited, see "Locking" in Mail::Box::Locker

       $obj->isLocked()
           Inherited, see "Locking" in Mail::Box::Locker

       $obj->lock()
       $obj->unlock()
           Inherited, see "Locking" in Mail::Box::Locker

   Error handling
       Extends "Error handling" in Mail::Box::Locker.

       $obj->AUTOLOAD()
           Inherited, see "Error handling" in Mail::Reporter

       $obj->addReport($object)
           Inherited, see "Error handling" in Mail::Reporter

       $obj->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level, $callback] )
       Mail::Box::Locker::NFS->defaultTrace( [$level]|[$loglevel, $tracelevel]|[$level,
       $callback] )
           Inherited, see "Error handling" in Mail::Reporter

       $obj->errors()
           Inherited, see "Error handling" in Mail::Reporter

       $obj->log( [$level, [$strings]] )
       Mail::Box::Locker::NFS->log( [$level, [$strings]] )
           Inherited, see "Error handling" in Mail::Reporter

       $obj->logPriority($level)
       Mail::Box::Locker::NFS->logPriority($level)
           Inherited, see "Error handling" in Mail::Reporter

       $obj->logSettings()
           Inherited, see "Error handling" in Mail::Reporter

       $obj->notImplemented()
           Inherited, see "Error handling" in Mail::Reporter

       $obj->report( [$level] )
           Inherited, see "Error handling" in Mail::Reporter

       $obj->reportAll( [$level] )
           Inherited, see "Error handling" in Mail::Reporter

       $obj->trace( [$level] )
           Inherited, see "Error handling" in Mail::Reporter

       $obj->warnings()
           Inherited, see "Error handling" in Mail::Reporter

   Cleanup
       Extends "Cleanup" in Mail::Box::Locker.

       $obj->DESTROY()
           Inherited, see "Cleanup" in Mail::Box::Locker

DIAGNOSTICS

       Warning: Folder $folder already locked over nfs
           Do not try to lock the folder when the application already has the lock: it will give
           you dead-locks.

       Error: Package $package does not implement $method.
           Fatal error: the specific package (or one of its superclasses) does not implement this
           method where it should. This message means that some other related classes do
           implement this method however the class at hand does not.  Probably you should
           investigate this and probably inform the author of the package.

       Warning: Removed expired lockfile $filename.
           A lock file was found which was older than the expiration period as specified with
           new(timeout).  The lock file was successfully removed.

       Error: Unable to remove expired lockfile $lockfile: $!
           A lock file was found which was older than the expiration period as specified with the
           new(timeout) option.  It is impossible to remove that lock file, so we need to wait
           until it vanishes by some external cause.

SEE ALSO

       This module is part of Mail-Box distribution version 3.004, built on December 22, 2017.

       Do not forget to read Mail::Box-Overview, Mail::Box-Cookbook, and Mail::Box-Index.
       Examples are included in the Mail-Box distribution, directories 'examples' and 'scripts'.

       Browseable manuals, papers, and other released material van be found at  Website:
       http://perl.overmeer.net/mailbox/

       The central modules (in separate distributions) in the MailBox suite are: Mail::Message,
       Mail::Box, Mail::Box::IMAP4, Mail::Box::POP3, Mail::Box::Parser::C, Mail::Box::Dbx
       (unpublished), Mail::Transport, Object::Realize::Later, and User::Identity.

       Please post questions or ideas to the author markov@cpan.org.

LICENSE

       Copyrights 2001-2017 by [Mark Overmeer]. For other contributors see ChangeLog.

       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.  See http://dev.perl.org/licenses/